Re: [time-nuts] Set time on Solaris computer from HP 58503A
Of *course* you can sync to better than a millisecond on the LAN. There's not a machine worldwide at my employer more than 600 micros off from each other, and the machines at my house are within 50. You wanna start talking the sync-e+1588 test I'm doing? We're speaking in nanos then. My LTE Lite is the only USB pps I have presently - and it pulls my time well over 200 milliseconds off reference. That's a massive change from the 1 or less I am from the internet and the 50 micros from the other boxes. NS On Sun, Dec 14, 2014 at 10:30 AM, Chris Albertson albertson.ch...@gmail.com wrote: I would still like to experiment with it. As I wrote earlier I bought this for a frequency reference, not a clock, but I would not object to a bit of fun messing around with it. If the goal is just getting good enough time onto the Solaris machine then use NTP and some pool servers on the Internet. You get about 10 millisecond level accuracy and the cost is zero. If you have solaris running you might even have this all setup and running. If not do this as the first step and verify it works. If 10ms is unacceptable, next step is to connect the PPS signal. Doing this will move you from milli to micro second level accuracy. It is easy if the Solaris machine has a real serial port. If you have to go through a USB dongle you loose about an order of magnitude accuracy but this is still very good. There is zero point in buying a special computer to run NTP. Just use any computer you own that is already running 24x7. Of course if you don't have a computer that runs 24x7 then you would look for one that uses very little power. Don't worry to much if the USB connection skews the time on the NTP server by some tens of microseconds, your server can't transfer time to your other computers on the LAN any better than millisecond level so a few tenths of an millisecond hardly mater. My opinion of computer time is that for normal use being a few milliseconds off is OK because the typical monitor is refreshed no faster than 100Hz so you have lag cause by screen refresh times even if the internal clock is dead-on perfect. Same for disk time stamps, these is lag in the IO system too -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
Of *course* you can sync to better than a millisecond on the LAN. There's not a machine worldwide at my employer more than 600 micros off from each other, and the machines at my house are within 50. You wanna start talking the sync-e+1588 test I'm doing? We're speaking in nanos then. My LTE Lite is the only USB pps I have presently - and it pulls my time well over 200 milliseconds off reference. That's a massive change from the 1 or less I am from the internet and the 50 micros from the other boxes. NS = Neil, Have you compared the PPS direct output of the LTE Lite for offset from true UTC? On serial-over-USB: my own tests with a different box, using PPS on the serial port DCD line over USB were much better than that, reducing jitter from 110-140 microseconds with a LAN connection to a stratum-1 source to 45 microseconds with a PPS/DCD over USB connection. http://www.satsignal.eu/ntp/NTP-on-Windows-serial-port.html#usb I may have been lucky with the particular serial-USB converter, though. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
Le 14 déc. 2014 à 10:02, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk a écrit : Both my computers run Solaris. * One, a Sun Ultra 27 has a Xeon processor, no serial ports, but I do have a good quality USB serial adapter for it. * The other, a Sun Blade 2000, has a SPARC processor a 25 pin serial port. I am using the Sun Blade 2000 to talk to the HP now, but I don't run that machine 24/7 due to the fact it is rather power hungry. The Xeon based machine is much more modern, much faster and uses a lot less power. I would like to be able to set the date time of the Xeon workstation from the HP 58503A. I appreciate that the USB is likely to cause some performance degradation compared to a real serial port, but I can live with that. If the serial driver will pass the DCD, so much the better. Can anyone advise if this is possible, and if so what software is needed? Any idea what sort of accuracy would be achievable? try ref clock driver 26 Type 26 http://www.eecis.udel.edu/%7Emills/ntp/html/drivers/driver26.html Hewlett Packard 58503A GPS Receiver (GPS_HP) I bought this to use as a frequency reference, not a clock, so I am not going to buy commercial software to do it, but if it can be done easily from open source software I will do so. Any suggestions? Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
drkir...@kirkbymicrowave.co.uk said: Can anyone advise if this is possible, and if so what software is needed? Any idea what sort of accuracy would be achievable? I'm not familiar with Solaris. I've never worked with a 58503A, but I have worked with the Z3801A and KS-24361. I'd try ntpd. There is probably a version that comes with Solaris. USB probably doesn't support PPS. I'd expect time to be within ballpark of 10s of ms, roughly what you would expect with a good network connection so use that as a sanity check. You will need to setup your ntp.conf to use the HP driver, 26. You will need to setup your 58503A to use UTC in T2 mode. :diag:gps:utc 1 (and reboot?) :ptime:tcode:format F2 You can check the GPS/UTC setting on the status page, and check the T2 setting by sending: :PTIME:TCODE? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
Based on my recent testing - including Solaris - you will be better off with the Internet unless your USB adapter is far better behaved than the several I have here On Sunday, December 14, 2014, Hal Murray hmur...@megapathdsl.net wrote: drkir...@kirkbymicrowave.co.uk javascript:; said: Can anyone advise if this is possible, and if so what software is needed? Any idea what sort of accuracy would be achievable? I'm not familiar with Solaris. I've never worked with a 58503A, but I have worked with the Z3801A and KS-24361. I'd try ntpd. There is probably a version that comes with Solaris. USB probably doesn't support PPS. I'd expect time to be within ballpark of 10s of ms, roughly what you would expect with a good network connection so use that as a sanity check. You will need to setup your ntp.conf to use the HP driver, 26. You will need to setup your 58503A to use UTC in T2 mode. :diag:gps:utc 1 (and reboot?) :ptime:tcode:format F2 You can check the GPS/UTC setting on the status page, and check the T2 setting by sending: :PTIME:TCODE? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com javascript:; To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
On 14 December 2014 at 11:57, Hal Murray hmur...@megapathdsl.net wrote: drkir...@kirkbymicrowave.co.uk said: Can anyone advise if this is possible, and if so what software is needed? Any idea what sort of accuracy would be achievable? I'm not familiar with Solaris. I've never worked with a 58503A, but I have worked with the Z3801A and KS-24361. I'd try ntpd. There is probably a version that comes with Solaris. I 1) Downloaded ntp-4.2.6p5 2) Configured with as ./configure --enable-HPGPS 3) Built it, without any problems. 4) Switched user to root 4) Disabled the ntpd which was already running # svcadm disable ntp 4) Installed it. I found it created a number of files in /usr/local/bin drkirkby@buzzard:~$ ls -lrt /usr/local/bin/ | grep Dec 14 -rwxr-xr-x 1 root root1394 Dec 14 12:19 ntp-wait -rwxr-xr-x 1 root root2029 Dec 14 12:19 ntptrace -rwxr-xr-x 1 root root 466252 Dec 14 12:19 sntp -rwxr-xr-x 1 root root 2253412 Dec 14 12:19 ntpd -rwxr-xr-x 1 root root 299696 Dec 14 12:19 ntpdate -rwxr-xr-x 1 root root 604280 Dec 14 12:19 ntpdc -rwxr-xr-x 1 root root 606312 Dec 14 12:19 ntpq -rwxr-xr-x 1 root root 176496 Dec 14 12:19 ntptime -rwxr-xr-x 1 root root 23288 Dec 14 12:19 tickadj -rwxr-xr-x 1 root root 460120 Dec 14 12:19 ntp-keygen and also the directory /dev/fd drkirkby@buzzard:~$ ls /dev/fd 0112 127 141 156 170 185 2213 228 242 27 41 56 70 85 1113 128 142 157 171 186 20 214 229 243 28 42 57 71 86 10 114 129 143 158 172 187 200 215 23 244 29 43 58 72 87 100 115 13 144 159 173 188 201 216 230 245 344 59 73 88 101 116 130 145 16 174 189 202 217 231 246 30 45 674 89 102 117 131 146 160 175 19 203 218 232 247 31 46 60 75 9 103 118 132 147 161 176 190 204 219 233 248 32 47 61 76 90 104 119 133 148 162 177 191 205 22 234 249 33 48 62 77 91 105 12 134 149 163 178 192 206 220 235 25 34 49 63 78 92 106 120 135 15 164 179 193 207 221 236 250 35 564 79 93 107 121 136 150 165 18 194 208 222 237 251 36 50 65 894 108 122 137 151 166 180 195 209 223 238 252 37 51 66 80 95 109 123 138 152 167 181 196 21 224 239 253 38 52 67 81 96 11 124 139 153 168 182 197 210 225 24 254 39 53 68 82 97 110 125 14 154 169 183 198 211 226 240 255 454 69 83 98 111 126 140 155 17 184 199 212 227 241 26 40 55 784 99 drkirkby@buzzard:~$ USB probably doesn't support PPS. I'd expect time to be within ballpark of 10s of ms, roughly what you would expect with a good network connection so use that as a sanity check. You will need to setup your ntp.conf to use the HP driver, 26. That I am not sure how to configure ntp.conf - a case of RTFM. You will need to setup your 58503A to use UTC in T2 mode. :diag:gps:utc 1 (and reboot?) That command works. How do you reboot - apart from of course powering the thing off? :ptime:tcode:format F2 That command works too. You can check the GPS/UTC setting on the status page, and check the T2 setting by sending: :PTIME:TCODE? E-101 :PTIME:TCODE? T220141214123441337 (remember I have not rebooted) Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
On Dec 14, 2014, at 07:42, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: On 14 December 2014 at 11:57, Hal Murray hmur...@megapathdsl.net redacted That command works. How do you reboot - apart from of course powering the thing off? # shutdown -y -i6 -g0 Or # reboot Or # init 6 Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
On 14 December 2014 at 12:39, Neil Schroeder gign...@gmail.com wrote: Based on my recent testing - including Solaris - you will be better off with the Internet unless your USB adapter is far better behaved than the several I have here The USB - serial adapter I have is an Keyspan USA-19HS http://www.tripplite.com/high-speed-usb-to-serial-adapter-keyspan~USA19HS/ I bought that one, as it was officially supported by Sun. I also have another one somewhere - forget which model. Again that was officially supported by Sun. Both have worked for industrial control applications, whereas I gather some cheap ones are only suitable for common consumer devices. In any case, it will be more fun educational to use the GPS receiver. To be honest, I don't need great accuracy. I only bought the unit as a frequency standard - the clock functionality is not important to me, but if I can have a bit of fun playing around with it, then I will. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
On 14 December 2014 at 13:37, bownes bow...@gmail.com wrote: On Dec 14, 2014, at 07:42, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: On 14 December 2014 at 11:57, Hal Murray hmur...@megapathdsl.net redacted That command works. How do you reboot - apart from of course powering the thing off? # shutdown -y -i6 -g0 Or # reboot Or # init 6 Bob I know those commands, although I don't recommend reboot - it is less clean than init 6. I assumed that that Hal Murry's reboot was meant to be the GPS receiver, not the Solaris computer, but maybe I mis-understood. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
Hi On Dec 14, 2014, at 8:38 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: On 14 December 2014 at 12:39, Neil Schroeder gign...@gmail.com wrote: Based on my recent testing - including Solaris - you will be better off with the Internet unless your USB adapter is far better behaved than the several I have here The USB - serial adapter I have is an Keyspan USA-19HS http://www.tripplite.com/high-speed-usb-to-serial-adapter-keyspan~USA19HS/ I bought that one, as it was officially supported by Sun. I also have another one somewhere - forget which model. Again that was officially supported by Sun. There are some long and detailed threads back in the archives about just how USB works and what this does to timing. Simple / quick summary: To do a proper / accurate time transfer, an edge from a source needs to be accurately clocked into the target machine. Any delay in this process is a bad thing. There are a lot of places delay can come from. USB is a packett / block transfer protocol. It gets it’s speed from sending a lot of stuff all at one time. When a serial USB sees a long string coming in, it formats it into a single block and transfers the whole thing in one bus transaction. That’s perfect for most things (commercial or consumer). The device gets on the bus and off the bus quickly with minimum overhead involved. Waiting on something like a pps string is a real bad idea. Your serial port is running at a rational baud rate. At 9600 baud, each character time you delay messes up the PPS timing by almost a millisecond. The PPS ID strings are many characters long. The impact on pps timing could (and often is) quite major. Even in the “best case” of sending the data one or two characters later, the pps is not very accurate. In the “worst case” it’s 10X or maybe 100X less accurate still. Some numbers: 1) PPS out of your GPSDO is likely 100 ns all the time. Most of the time (one sigma) it’s in the 10 to 30 ns range depending on which box you are running. 2) One character at 8N1 is 10 bits. At 9600 baud that’s 1.04 ms. It’s unlikely the USB sends in less than 1 character time. 3) A normal string is in the 30 to 40 characters range. A normal USB will buffer for 30X the character time ... NTP via ethernet, with well chosen servers, can get you down to 10 ms timing on you machines. It’s reliable and fairly easy to set up. The other alternative is to get the PPS edge into the machine in a more direct manner than USB. Yes I have a pile of SUN boxes, they often don’t come with all the i/o chards you might like to have…. Another alternative (and thus it’s popularity on the list) is to set up something small and light weight as a dedicated NTP server on your local LAN. That gets the timing issues of your local connection to the internet out of the NTP equation. You can get down under 10 us with a setup like that. The result may be better than your ability to time an edge on the SUN box, due to all the other overheads involved there. It’s also a nice stand alone project that is far less likely to mess up your main machine. The boards commonly used are $100 and some are much cheaper than that. Bob Both have worked for industrial control applications, whereas I gather some cheap ones are only suitable for common consumer devices. In any case, it will be more fun educational to use the GPS receiver. To be honest, I don't need great accuracy. I only bought the unit as a frequency standard - the clock functionality is not important to me, but if I can have a bit of fun playing around with it, then I will. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
I would still like to experiment with it. As I wrote earlier I bought this for a frequency reference, not a clock, but I would not object to a bit of fun messing around with it. If the goal is just getting good enough time onto the Solaris machine then use NTP and some pool servers on the Internet. You get about 10 millisecond level accuracy and the cost is zero. If you have solaris running you might even have this all setup and running. If not do this as the first step and verify it works. If 10ms is unacceptable, next step is to connect the PPS signal. Doing this will move you from milli to micro second level accuracy. It is easy if the Solaris machine has a real serial port. If you have to go through a USB dongle you loose about an order of magnitude accuracy but this is still very good. There is zero point in buying a special computer to run NTP. Just use any computer you own that is already running 24x7. Of course if you don't have a computer that runs 24x7 then you would look for one that uses very little power. Don't worry to much if the USB connection skews the time on the NTP server by some tens of microseconds, your server can't transfer time to your other computers on the LAN any better than millisecond level so a few tenths of an millisecond hardly mater. My opinion of computer time is that for normal use being a few milliseconds off is OK because the typical monitor is refreshed no faster than 100Hz so you have lag cause by screen refresh times even if the internal clock is dead-on perfect. Same for disk time stamps, these is lag in the IO system too -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
gign...@gmail.com said: Based on my recent testing - including Solaris - you will be better off with the Internet unless your USB adapter is far better behaved than the several I have here That depends, (TM) How good/bad is your network connection? Mine gets over 3 seconds of queuing delays. I challenge anybody to find a USB device that bad. There are only 2 or 3 significant vendors of USB-serial chips. I think they are reasonably well supported by all major OSes. USB is polled, so interrupt latency turns into polling latency. I think the polling cycle is 1 ms for slow things like serial ports. Maybe 1/4 ms for faster things like disks. At the system level, faster polling means more overhead and slower polling means bigger buffers. Many of the low cost GPS units use the SiRF chips. They have a wander of ~100 ms. I said wander rather than jitter because it's very slow as in hours. You can't filter it out with a 10 or 100 second sample. The old Garmin GPS-18-USB (not 18x) units had pretty good timing. No wander. Unfortunately, they weren't very sensitive. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
Hi On Dec 14, 2014, at 4:26 PM, Hal Murray hmur...@megapathdsl.net wrote: gign...@gmail.com said: Based on my recent testing - including Solaris - you will be better off with the Internet unless your USB adapter is far better behaved than the several I have here That depends, (TM) How good/bad is your network connection? Mine gets over 3 seconds of queuing delays. I challenge anybody to find a USB device that bad. There are only 2 or 3 significant vendors of USB-serial chips. I think they are reasonably well supported by all major OSes. USB is polled, so interrupt latency turns into polling latency. I think the polling cycle is 1 ms for slow things like serial ports. On at least some (= the ones I’ve seen) of the serial devices, they will continue to buffer if they have a character coming in. Put another way, a string sent at 19.2 Kbaud will likely transfer as a block rather than a character at a time. Is this at the bus or the driver level? - who knows. The result (in Linux / Win-dooze / or OS-X) is that data comes in in bursts. Maybe 1/4 ms for faster things like disks. At the system level, faster polling means more overhead and slower polling means bigger buffers. Many of the low cost GPS units use the SiRF chips. They have a wander of ~100 ms. I said wander rather than jitter because it's very slow as in hours. You can't filter it out with a 10 or 100 second sample. .. as in a pps output is not necessarily a *useful* pps output. Only useful outputs count. We’ve been over the why and the how of chips that put out pps’s way late a number of times. Simple answer - it didn’t matter in the firmware design spec. Bob The old Garmin GPS-18-USB (not 18x) units had pretty good timing. No wander. Unfortunately, they weren't very sensitive. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Set time on Solaris computer from HP 58503A
1) Downloaded ntp-4.2.6p5 If you are going to compile it (rather than use whatever comes with your system), please use the Release Candidate version from: http://support.ntp.org/bin/view/Main/SoftwareDownloads [Anybody else willing to help... This is your chance. If you find bugs, submit a bug report and/or poke me off list.] and also the directory /dev/fd That's something else. I don't know what they are. My guess would be something associated with the file system. That I am not sure how to configure ntp.conf - a case of RTFM. It's probably as simple as adding server 127.127.26.0 but read the driver26.html page You also need something like: ln -s /dev/ttyS0 /dev/hpgps0 How do you reboot - apart from of course powering the thing off? Yes. Power cycle. E-101 :PTIME:TCODE? T220141214123441337 You can sanity check the UTC/GPS by eyeball. They are 16 seconds apart. You can clear the E-101 (and get back to scpi) by sending: *CLS I know those commands, although I don't recommend reboot - it is less clean than init 6. I assumed that that Hal Murry's reboot was meant to be the GPS receiver, not the Solaris computer, but maybe I mis-understood. Yes. Power cycle the GPSDO. At least on the Z3801A, it's stored in flash. You only have to do it once. I think there is a software command to reboot. I don't have it handy. Mostly, I work from the Z3801A manual. A few things don't work on the KS-24361. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
